Circulating Nucleic Acid-Based Biomarkers of Type 2 Diabetes

Type 2 diabetes (T2D) is a deficiency in how the body regulates glucose. Uncontrolled T2D will result in chronic high blood sugar levels, eventually resulting in T2D complications. These complications, such as kidney, eye, and nerve damage, are even harder to treat. Identifying individuals at high risk of developing T2D and its complications is essential for early prevention and treatment. Numerous studies have been done to identify biomarkers for T2D diagnosis and prognosis. This review focuses on recent T2D biomarker studies based on circulating nucleic acids using different omics technologies: genomics, transcriptomics, and epigenomics. Omics studies have profiled biomarker candidates from blood, urine, and other non-invasive samples. Despite methodological differences, several candidate biomarkers were reported for the risk and diagnosis of T2D, the prognosis of T2D complications, and pharmacodynamics of T2D treatments. Future studies should be done to validate the findings in larger samples and blood-based biomarkers in non-invasive samples to support the realization of precision medicine for T2D.

Liquid Biopsies in Epilepsy: Biomarkers for Etiology, Diagnosis, Prognosis, and Therapeutics

Epilepsy is one of the most common disorders of the central nervous system, impacting nearly 50 million people around the world. Heterogeneous in nature, epilepsy presents in children and adults alike. Currently, surgery is the only treatment that can cure epilepsy. However, not all individuals are eligible or have successful outcomes. Difficulty in accessing samples of human brain tissue along with advances in sequencing technology have driven researchers to investigate sampling liquid biopsies in blood, serum, plasma, and cerebrospinal fluid within the context of epilepsy. Liquid biopsies provide minimal or non-invasive sample collection approaches and can be assayed relatively easily across multiple time points, unlike tissue-based sampling. Various efforts have investigated circulating nucleic acids from these samples including microRNAs, cell-free DNA, transfer RNAs, and long non-coding RNAs. Here, we review nucleic acid-based liquid biopsies in epilepsy to improve understanding of etiology, diagnosis, prediction, and therapeutic monitoring.

Annealed ZnO/Al2O3 Core-Shell Nanowire as a Platform to Capture RNA in Blood Plasma

RNA analytical platforms gained extensive attention recently for RNA-based molecular analysis. However, the major challenge for analyzing RNAs is their low concentration in blood plasma samples, hindering the use of RNAs for diagnostics. Platforms that can enrich RNAs are essential to enhance molecular detection. Here, we developed the annealed ZnO/Al2O3 core-shell nanowire device as a platform to capture RNAs. We showed that the annealed ZnO/Al2O3 core-shell nanowire could capture RNAs with high efficiency compared to that of other circulating nucleic acids, including genomic DNA (gDNA) and cell-free DNA (cfDNA). Moreover, the nanowire was considered to be biocompatible with blood plasma samples due to the crystalline structure of the Al2O3 shell which serves as a protective layer to prevent nanowire degradation. Our developed device has the potential to be a platform for RNA-based extraction and detection.

Large Scale Molecular Studies of Pituitary Neuroendocrine Tumors: Novel Markers, Mechanisms and Translational Perspectives

Pituitary neuroendocrine tumors (PitNETs) are non-metastatic neoplasms of the pituitary, which overproduce hormones leading to systemic disorders, or tumor mass effects causing headaches, vertigo or visual impairment. Recently, PitNETs have been investigated in large scale (exome and genome) molecular analyses (transcriptome microarrays and sequencing), to uncover novel markers. We performed a literature analysis on these studies to summarize the research data and extrapolate overlapping gene candidates, biomarkers, and molecular mechanisms. We observed a tendency in samples with driver mutations (GNAS, USP8) to have a smaller overall mutational rate, suggesting driver-promoted tumorigenesis, potentially changing transcriptome profiles in tumors. However, direct links from drivers to signaling pathways altered in PitNETs (Notch, Wnt, TGF-β, and cell cycle regulators) require further investigation. Modern technologies have also identified circulating nucleic acids, and pinpointed these as novel PitNET markers, i.e., miR-143-3p, miR-16-5p, miR-145-5p, and let-7g-5p, therefore these molecules must be investigated in the future translational studies. Overall, large-scale molecular studies have provided key insight into the molecular mechanisms behind PitNET pathogenesis, highlighting previously reported molecular markers, bringing new candidates into the research field, and reapplying traditional perspectives to newly discovered molecular mechanisms.

O64: GENOMIC PROFILING USING CIRCULATING NUCLEIC ACIDS IN STAGE IV MELANOMA PATIENTS RECEIVING IMMUNOTHERAPY REVEALS A NOVEL GENE AMPLIFICATION LANDSCAPE AND ALLOWS FOR DETECTION OF ACTIONABLE GENE MUTATIONS

Introduction Serial monitoring for disease progression and therapeutic efficacy at the molecular level in metastatic melanoma is hampered by a lack of reliable blood borne biomarkers. Molecular profiling of melanoma tumours is almost impractical in metastatic disease due to risks of procedure related morbidity and sampling inefficiency in representing tumour heterogeneity. Cell free DNA allows monitoring of molecular changes in melanoma over the course of immunotherapy. We investigated the utility of somatic mutation and gene amplification analyses in melanoma patients receiving immunotherapy. Method Cell free DNA was extracted from plasma using a QIAamp Circulating Nucleic Acid Kit (Qiagen). Pathway focused profiling of somatic mutation status was performed by ARMs PCR using QBiomarker Somatic Mutation PCR Arrays (Qiagen). Gene amplification analysis was performed by Real Time Quantitative PCR (Roche) using RT2 Profiler PCR Arrays (Qiagen). Result A total of twenty patients with stage IV melanoma receiving immunotherapy were enrolled in this study. The BRAF p.V600E mutation was detected in the cfDNA of 80% of BRAF positive patients. Cell free DNA was also profiled for a total of 84 genes of the cancer inflammation and immunity pathway. There was a significant difference in the copy numbers of several genes (CTLA-4, CXCL12, CXCL5, IDO1, TGFB, IFNG, IL4, PTGS2, AICDA, HLA-A, CCL4, ACKR3, TP53, MYC) between patients with progressive disease and therapeutic response (n=20, p < 0.05). Conclusion We postulate that cell free DNA pathway focused somatic mutation and gene amplification analyses may be useful in evaluating disease progression and therapeutic response. Take-home message Genomic analysis of circulating nucleic acids may be useful in evaluating disease progression and therapeutic response in metastatic melanoma.